Toán 2/3x-1/2x=5/2 (3x/7+1):(-4)=-1/28 (3/7-1/4+5/14):x=15% 06/09/2021 By Eden 2/3x-1/2x=5/2 (3x/7+1):(-4)=-1/28 (3/7-1/4+5/14):x=15%
2/3x-1/2x=5/2 ⇔ x(2/3 – 1/2) = 5/2 ⇔ x . 1/6 = 5/2 ⇔ x = 5/2 : 1/6 ⇔ x = 15 (3x/7+1):(-4)=-1/28 ⇔ 3x/7 + 1 = -1/28 .(-4) ⇔ 3x/7 + 1 = 1/7 ⇔ 3x/7 = 1/7 – 1 ⇔3x/7 = -6/7 ⇔x = -6/7 : 3/7 ⇔ x = -2 (3/7-1/4+5/14):x=15% ⇔ 15/28 : x = 3/20 ⇔ x = 15/28 : 3/20 ⇔ x = 25/7 Trả lời
Đáp án: Giải thích các bước giải: a, `2/3`x – `1/2`x = `5/2` (`2/3`-`1/2`). x = `5/2` (`4/6`- `3/6` ) .x = `5/2` `1/6` . x = `5/2` x = `5/2`:`1/6` x = `5/2` – `6/1` x = `30/2` = 15 Vậy x = 15 b,( `3x/7+1` ) : ( -4 ) = `-1/28` `3x/7+1` = `-1/28` . ( -4 ) `3x/7+1` = `1/7` `3x/7` = `1/7`- 1 `3x/7` = `-6/7` Vậy x = `-6/7` c, (`3/7`-`1/4`+`5/14`) : x=15% (`3/7`-`1/4`+`5/14`) : x=`3/20` ( `12/28` – `7/28` + `10/28` ) : x = `3/20` ( 5/28 + 10/28 ) : x = 3/20 `15/28` : x = `3/20` x = `15/28` : `3/20` x = `15/28` . `20/3` x = `300/84` = `25/7` Vậy x = `25/7` Chúc bạn học tốt ! @caohalinh2008 Trả lời
2/3x-1/2x=5/2
⇔ x(2/3 – 1/2) = 5/2
⇔ x . 1/6 = 5/2
⇔ x = 5/2 : 1/6
⇔ x = 15
(3x/7+1):(-4)=-1/28
⇔ 3x/7 + 1 = -1/28 .(-4)
⇔ 3x/7 + 1 = 1/7
⇔ 3x/7 = 1/7 – 1
⇔3x/7 = -6/7
⇔x = -6/7 : 3/7
⇔ x = -2
(3/7-1/4+5/14):x=15%
⇔ 15/28 : x = 3/20
⇔ x = 15/28 : 3/20
⇔ x = 25/7
Đáp án:
Giải thích các bước giải:
a, `2/3`x – `1/2`x = `5/2`
(`2/3`-`1/2`). x = `5/2`
(`4/6`- `3/6` ) .x = `5/2`
`1/6` . x = `5/2`
x = `5/2`:`1/6`
x = `5/2` – `6/1`
x = `30/2` = 15
Vậy x = 15
b,( `3x/7+1` ) : ( -4 ) = `-1/28`
`3x/7+1` = `-1/28` . ( -4 )
`3x/7+1` = `1/7`
`3x/7` = `1/7`- 1
`3x/7` = `-6/7`
Vậy x = `-6/7`
c, (`3/7`-`1/4`+`5/14`) : x=15%
(`3/7`-`1/4`+`5/14`) : x=`3/20`
( `12/28` – `7/28` + `10/28` ) : x = `3/20`
( 5/28 + 10/28 ) : x = 3/20
`15/28` : x = `3/20`
x = `15/28` : `3/20`
x = `15/28` . `20/3`
x = `300/84` = `25/7`
Vậy x = `25/7`
Chúc bạn học tốt !
@caohalinh2008